Nextgen code showing on homepage post previews/descriptions

I believe the nextgen plugin is causing a bug on the homepage of a blog that I am helping somebody with.

I have uploaded a screenshot to show exactly what I mean.

https://i.imgur.com/1mAgX.jpg

Any help on fixing this problem would be massively appreciated. Thank you ??

https://www.ads-software.com/extend/plugins/nextgen-gallery/